Sweing machine



1930. N. v. CHRISTENSEN ET AL 1,773,075

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SEWING MACHINE Filed May 21, 1927 8 Sheets-Sheet 8 Patented Aug. 12, 1930 UNITED STATES PATENT OFFICE NORMAN V. CHRISTENSEN AND WALTER M. HANNEMAN, OF CHICAGO, ILLINOIS, AS- SIGNORS TO UNION SPECIAL MACHINE COMPANY,OF CHICAGO, ILLINOIS, A COR- PORATION OF ILLINOIS SEWING MACHINE Application filed May 21, 1927. Serial No. 193,340.

The invention relates to new and useful improvements in sewing machines, and more particularly to a sewing machine having a. suspended work supporting arm and a needle head overhanging the end of said arm.

An object of the invention is to provide a sewing machine having a supporting frame in which the main actuating shaft is mounted, and on which is detachably mounted a needle head carrying the upper seam forming elements and also detachably mounted a suspended work supporting arm carrying the under seam forming elements.

A further object of the invention is to provide a machine of the above type wherein the upper seam forming elements are all actuated from a single eccentric member formed in the actuating shaft, and wherein said actuating mechanism is of such a character that the needle head may be readily detached and interchanged with a different needle head having a different arrangement of upper seaming elements, and wherein the work supporting arm may be detached and another arm substituted therefor having a different arrangement of seaming elements, and thus the machine modified so as to produce different types of stitching machines.

A further object of the invention is to provide a supporting frame having an actuating shaft mounted therein, to which may be attached selected elements for creating sew ing machines adapted to operate upon different kinds of material.

, These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by way of iilustration one embodiment of the invention Figure 1 is a plan view of a sewing machine embodying the improvements, with the cover plates removed to show the mechanism beneath the same;

Fig. 2 is an end view of the supporting frame of'the machine with the needle head and arm detached;

Fig. 31's a sectional view through the frame and needle head, looking to the right as viewed in Fig. 1;

Fig. 4 is a sectional view through the frame showing the end housing supporting the lrlieegle head, and a modified form of needle Fig. 5 is a plan view of the end of the frame and the needle head shown in Fig. 4;

Fig. 6 is a view partly in front elevation and partly in section, showing the machine equipped with a needle head such as shown in Fig. 3;

7 is a side view of the detached arm;

Fig. 8 is a view partly in section and partly in side elevation showing the work arm with a differential feeding mechanism there- 1n.

The invention is directed broadly to a sewing machine which includes a supporting frame or base on which are detachably mounted a needle head and a suspended work supporting arm. The frame includes a base member and a bracket portion, the upper end of which overhangs the base and is provided with a housing or frame member in which the main. shaft is mounted. Extending forwardly from this housing or frame member containing the main shaft is a projecting housing, to the outer end of which a needle head is detachably connected. This needle head may be modified for different characters of stitching. When independent lines of stitching alone are desired, then a needle head is attached containing a needle bar carrying the needles and a presser bar carrying the presser foot. The needle bar is actuatedv by a lever which is connected to a link cooperating with an eccentric in the main actuating shaft. This lever is preferably mounted in the housing which is integral with the supporting frame. By detaching the lever from the needle bar. the needle head may be disconnected from the frame and another needle head substituted therefor, for stitching knit goods, if desired. In case such a needle head is attached to the frame. it will have the needle bar with a plurality of needles, a similar type of presser bar and presser foot, a cross thread laying mechanism and a trimming mechanism. The needles and the cross thread laying mechanism, together with the trimming mechanism, constitute what might be referred to as the up-' ers to cooperate with the needles, and a feeding mechanism for feeding the material. The loopers and feeding mechanism may be said to constitute the under seam forming elements. In the case of straight lines of stitching, there will, of course, be a looper for each.

needle. As such a machine would be especially adapted for operating upon woven fabrics, a single feed dog is all that is necessary. The parts in this suspended arm are actuated by members extending through the depending portion carrying the arm and connected to the main shaft for actuation. These parts are all mounted in the arm, except for their connections to the shaft, and therefore, when the arm is detached and removed, the actuating mechanism contained therein is fully assembled. In case a needle head is selected for stitching knit fabrics, then a proper complemental stitch forming element is mounted in the arm and a differential feeding mechanism assembled in the arm. The broad invention consists in this supporting frame, to which is detachablv connected interchangeable needle heads an which have the seaming elements thereof readily interchanged. Thus it is that various types of sewing machines may be built up on the same supporting frame.

The details of the mechanism selected form no part of the present invention, and only'a brief description will be necessary in order to enable one skilled in the art to understand the invention, and understand how interchangeable needle heads may be provided, and also interchangeable work supporting arms.

The machine consists of a supporting frame having a base portion 1, and a bracket portion 2, which is shaped so as to overhang the forward edge of the base portion 1. At

the upper edge portion of the bracket 2 is a housing or frame member 3 in which is mounted the main actuating shaft 4. The main actuating shaft 4 is provided with a suitable beltwheel 5 and a hand wheel 6. The supporting frame has a forwardly projecting housing 7 adjacent the belt wheel.

and to this housing is adapted to be attached the needle head 8 as shown in Fig. 3, or a needle head 9, as shown in Figures 4 and 5.

The needle head 8 is provided with a housing10 which is adapted to be secured to the housing 7. The housing 10 as shown in Fig. 3, is provided with horizontal portions 11, 11 adapted to be secured to cross portions 12, 12 by suitable bolts 13, 13,

The housing 10 is provided with a needle bar 14 and also with a presser bar 15. The

; needle bar 14, as shown in Fig. 6, is provided interchangeable arms, or arms with two needles 16, 16. The needle bar is reciprocated by a lever 17 which is connected to the needle bar by means of a link 18. The lever 17 is fixed to a shaft 19 which is mounted in suitable bearings in the housing 7. The lever is oscillated by means of a link 20 which is connected to a crank 21formed in the main actuating shaft 4.. By detaching the connection between the lever 17 and the needle bar, and removing the bolts 13, 13, the needle head 8 may be detached from the frame. The needle head with the two needles mounted thereon, as described above, is particularly adapted for forming independent lines of stitching in woven fabrics.

The main supporting frame is also provided with a depending portion 22 which is open at its lower end, and a work supporting arm 23 is detachably secured thereto by.

means of bolts 24, 24. The work supporting arm is suspended, and is of a' type for doing tubular work, the material being fed off from the end of the arm. When it is desired to stitch fabric sections with two independent lines of stitching then a work arm is selected such as shown in Fig. 6 and when it is desired to stitch knit fabrics with aneedle head such as shown in Fig. 4, then a work arm is selected which is provided with a single looper cooperating with the three needles and a differential feeding mechanism for feeding the material. The construction of the work arm as shown in detail in Fig. 6 will be briefly described. Located within this work supporting arm is a shaft 25 which is provided with two loopers 26, 26, one for each needle. Thelooper shaft is oscillated by means of a link 27 which cooperates with a. crank 28 on the main actuating shaft 4. The material is fed oiffrom the end of the work supporting arm by means of a feed dog 29. The feed dog is carried by a feed bar 30 which is raised and lowered at its feeding end by alink 31 cooperating with an eccentric -32 on the main shaft-4. I The feed dog is moved back and forth for feeding the material by an endwise movement of the feed bar 30 and this is brought about by a linlr 33, cooperating with an eccentric 34 on 'the main actuating shaft 4. The looper shaft is moved endwise for giving a needle avoiding movement to the looper, bv a link 35, cooperating with an eccentric 36 on the main actuating shaft 4; -It will be apparent from Fig. 6 of the drawings. that the links or eccentric straps ,may be leadilydisconnected from the eccentrics and crank on the main actuating shaft, and the suspended arm 23 may then be detached from the frame of' separate units and t therein, may be attached to the frame and the parts to be actuated connected to the shaft. A work supporting arm with the parts assembled therein may also be selected and attached to the frame and the actuated parts connected to the actuating shaft. Thus it is that a machine may be built up and completed by a com leting of the machine in he attaching of the units to the frame unit carrying the main actuating shaft.

It will also be readil understood that the same frame unit may fi e used in connection with needle heads havin assembled therein, seam forming elements for operating upon a selected material for forming the desired seam. For example, if it is desired to operate upon knit goods, trim the edges as they are joined, and join the edges in a flat covered seam, then a sewing head is selected having the sewing elements for accomplishing such result. In Figures 4 and 5, we have shown such a needle head. It includes a housin 37 similar to the housing 10 above describe This housing is secured to the housin 7 of the frame by bolts 13 13 passing throu li members on the housing 37 and threa ed into the cross members 12, 12. Mounted for reciprocation in this housing 37 is a needle bar 38 carrying three needles 39, 40 and 41. The needle bar is actuated from the lever 17 by a link 18 similar to that described in connection with the needle head shown in Fig. 3.

Mounted in the needle head 9 is a vertical shaft 42. This vertical shaft is oscillated by a link 43 connected to a crank 44 on the shaft 19 which is oscillated with the lever 17. Cooperating with the needles are cover thread laying devices 45 and 46. These devices are oscillated by suitable connections with the shaft 42. Operating upon the material in advance of the needles is a trimming mechanism including a movable trimming, blade 47 and this movable trimming blade is also oscillated by suitable connections with the shaft 42. The machine, of course, is provided with a suitable presser foot for guiding the upturned edge portions of the fabrics which are to be stitched, and the stationary member of the trimming mechanism is mounted on the presser foot. As noted above, these specific elements form no part of the present invention, and have been referred to in order to make clear the type of needle head which may be connected to the unit supporting frame for stitching knit fabrics and forming flat seams therein.

When the needle head is selected for stitching knit fabrics then a work supporting arm is necessary which is provided with a proper complemental stitch forming mechanism and a proper feeding mechanism. Such a work arm is shown in Fig. 8 and a brief description of the structure contained therein will now be given. Located within the work su porting arm 23 is a looper supporting shaft 25 on which is mounted a single looper 26". This looper cooperates with all three needles. The looper shaft 25 is oscillated and moved endwise. It receives its oscillations from the link 27 and it is moved endwise through suitable connections with the eccentric strap 33, such as described in connection with Fig. 1. Located within the arm is a main feed dog 29 carried by a feed bar 30 which is moved back and forth by a link construction similar to that shown in Fig. 6, which is operated bv an eccentric strap 31 through a suitable lever connected to the feed bar by supporting links. Mounted on this feed bar is an auxiliary feed bar 30 carrying a feed dog 29. The

auxiliary feed bar is raised and lowered with the main feed bar and is moved back and forth by means of a link 30 (shown in dotted lines) connected to a rock lever 30 oscillated by a link 30 connected to the main feed bar. This work arm is connected to the supporting frame and the eccentric straps attached to the eccentrics on the main shaft precisely as described in connection with the work arm shown in Fig. 6.

From the above, it will be apparent that a unit needle head capable of forming a flat seam in a knit fabric may be selected and attached to this unit supporting frame. In this case, of course, a unit work supporting arm will be selected capable of operation with the selected unit needle head and the work supporting arm selected will be attached to the same unit frame. Further advantages are derived from the interchangeability of the needle heads and the work arms in connection with a common unit work supporting frame, but it is not thought necessary to describe them in detail.

The interchangeable head per se, and the specific mechanism contained therein, forms the subject-matter of our co-pending application Serial No. 130,194, filed August 19, 1926. The detachable suspended work supporting arm per se is shown, described and claimed in the Berger application Serial N 0. 88,298, filed February 15, 1926.

It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what we claim as new and desire to secure by Let ters Patent, is l 1. The combination of a supporting frame, a unit needle head and a cooperating unit work arm for forming one character of stitching, a unit needle head and cooperating work arm for forming a different character of stitchin and means for interchangeably connectmg either of said unit heads and its cooperating unit work arm to said frame whereby sewing machines may be assembled on said frame for forming stitches and scams having different characteristics.

2. The combination of a supporting frame, a unit needle head and a cooperating unit work arm for forming independent parallel lines of stitching, a unit needle head and a cooperating unit work arm for forming connected rows of stitching, and means for interchangeably connecting either of said unit heads and its cooperating unit work arm to said frame whereby sewing machines may be assembled on said frame for forming stitches and seams having different characteristics.

3. The combination of a unit supporting frame including a base, an overhanging bracket, a housing at the upper end of said bracket, said housing having a projecting housing at one end thereof and a depending member at the other end thereof, a unit needle head and a cooperating unit work arm for forming parallel lines of stitching, a unit needle head and a cooperating unit work arm for forming connected rows of stitching, and means for interchangeably connecting either of said unit heads to said projecting housing and its cooperating unit work arm to said depending member of said frame whereby sewing machines may be assembled on said frame for forming stitches and scams having different characteristics.

4. The combination of a unit supporting frame including a base, an overhanging ln acket, a housing at the upper end of said bracket, a main shaft located in said housing, said housing having a projecting housing at one end thereof and a depending member at the other end thereof, a unit needle head and a cooperating unit work arm for forming independent parallel lines of stitching, a unit needle head and a cooperating unit work arm for forming connected rows of stitching, and means for interchangeably connecting either of said unit heads and its cooperating unit work arm to said frame whereby the operating parts within said head and within said arm may be actuated from said shaft through the projecting housing and the depending member and sewing machines assembled on said frame for forming stitches and seams having different characteristics.

In testimony whereof, we aflix our signaturcs.

NORMAN V. CHRISTENSEN. \VALTER M. HANNEMAN. 

